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1// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2//
3// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
4// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
5
6#include <linux/bitops.h>
7#include <linux/device.h>
8#include <linux/hwmon.h>
9#include <linux/module.h>
10#include <linux/platform_data/mlxreg.h>
11#include <linux/platform_device.h>
12#include <linux/regmap.h>
13#include <linux/thermal.h>
14
15#define MLXREG_FAN_MAX_TACHO 12
16#define MLXREG_FAN_MAX_STATE 10
17#define MLXREG_FAN_MIN_DUTY 51 /* 20% */
18#define MLXREG_FAN_MAX_DUTY 255 /* 100% */
19/*
20 * Minimum and maximum FAN allowed speed in percent: from 20% to 100%. Values
21 * MLXREG_FAN_MAX_STATE + x, where x is between 2 and 10 are used for
22 * setting FAN speed dynamic minimum. For example, if value is set to 14 (40%)
23 * cooling levels vector will be set to 4, 4, 4, 4, 4, 5, 6, 7, 8, 9, 10 to
24 * introduce PWM speed in percent: 40, 40, 40, 40, 40, 50, 60. 70, 80, 90, 100.
25 */
26#define MLXREG_FAN_SPEED_MIN (MLXREG_FAN_MAX_STATE + 2)
27#define MLXREG_FAN_SPEED_MAX (MLXREG_FAN_MAX_STATE * 2)
28#define MLXREG_FAN_SPEED_MIN_LEVEL 2 /* 20 percent */
29#define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF 44
30#define MLXREG_FAN_TACHO_DIV_MIN 283
31#define MLXREG_FAN_TACHO_DIV_DEF (MLXREG_FAN_TACHO_DIV_MIN * 4)
32#define MLXREG_FAN_TACHO_DIV_SCALE_MAX 64
33/*
34 * FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
35 * The logic in a programmable device measures the time t-high by sampling the
36 * tachometer every t-sample (with the default value 11.32 uS) and increment
37 * a counter (N) as long as the pulse has not change:
38 * RPM = 15 / (t-sample * (K + Regval)), where:
39 * Regval: is the value read from the programmable device register;
40 * - 0xff - represents tachometer fault;
41 * - 0xfe - represents tachometer minimum value , which is 4444 RPM;
42 * - 0x00 - represents tachometer maximum value , which is 300000 RPM;
43 * K: is 44 and it represents the minimum allowed samples per pulse;
44 * N: is equal K + Regval;
45 * In order to calculate RPM from the register value the following formula is
46 * used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in the
47 * default case is modified to:
48 * RPM = 15000000 * 100 / ((Regval + 44) * 1132);
49 * - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
50 * - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
51 * In common case the formula is modified to:
52 * RPM = 15000000 * 100 / ((Regval + samples) * divider).
53 */
54#define MLXREG_FAN_GET_RPM(rval, d, s) (DIV_ROUND_CLOSEST(15000000 * 100, \
55 ((rval) + (s)) * (d)))
56#define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
57#define MLXREG_FAN_PWM_DUTY2STATE(duty) (DIV_ROUND_CLOSEST((duty) * \
58 MLXREG_FAN_MAX_STATE, \
59 MLXREG_FAN_MAX_DUTY))
60#define MLXREG_FAN_PWM_STATE2DUTY(stat) (DIV_ROUND_CLOSEST((stat) * \
61 MLXREG_FAN_MAX_DUTY, \
62 MLXREG_FAN_MAX_STATE))
63
64/*
65 * struct mlxreg_fan_tacho - tachometer data (internal use):
66 *
67 * @connected: indicates if tachometer is connected;
68 * @reg: register offset;
69 * @mask: fault mask;
70 */
71struct mlxreg_fan_tacho {
72 bool connected;
73 u32 reg;
74 u32 mask;
75};
76
77/*
78 * struct mlxreg_fan_pwm - PWM data (internal use):
79 *
80 * @connected: indicates if PWM is connected;
81 * @reg: register offset;
82 */
83struct mlxreg_fan_pwm {
84 bool connected;
85 u32 reg;
86};
87
88/*
89 * struct mlxreg_fan - private data (internal use):
90 *
91 * @dev: basic device;
92 * @regmap: register map of parent device;
93 * @tacho: tachometer data;
94 * @pwm: PWM data;
95 * @samples: minimum allowed samples per pulse;
96 * @divider: divider value for tachometer RPM calculation;
97 * @cooling: cooling device levels;
98 * @cdev: cooling device;
99 */
100struct mlxreg_fan {
101 struct device *dev;
102 void *regmap;
103 struct mlxreg_core_platform_data *pdata;
104 struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
105 struct mlxreg_fan_pwm pwm;
106 int samples;
107 int divider;
108 u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
109 struct thermal_cooling_device *cdev;
110};
111
112static int
113mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
114 int channel, long *val)
115{
116 struct mlxreg_fan *fan = dev_get_drvdata(dev);
117 struct mlxreg_fan_tacho *tacho;
118 u32 regval;
119 int err;
120
121 switch (type) {
122 case hwmon_fan:
123 tacho = &fan->tacho[channel];
124 switch (attr) {
125 case hwmon_fan_input:
126 err = regmap_read(fan->regmap, tacho->reg, ®val);
127 if (err)
128 return err;
129
130 *val = MLXREG_FAN_GET_RPM(regval, fan->divider,
131 fan->samples);
132 break;
133
134 case hwmon_fan_fault:
135 err = regmap_read(fan->regmap, tacho->reg, ®val);
136 if (err)
137 return err;
138
139 *val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
140 break;
141
142 default:
143 return -EOPNOTSUPP;
144 }
145 break;
146
147 case hwmon_pwm:
148 switch (attr) {
149 case hwmon_pwm_input:
150 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
151 if (err)
152 return err;
153
154 *val = regval;
155 break;
156
157 default:
158 return -EOPNOTSUPP;
159 }
160 break;
161
162 default:
163 return -EOPNOTSUPP;
164 }
165
166 return 0;
167}
168
169static int
170mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
171 int channel, long val)
172{
173 struct mlxreg_fan *fan = dev_get_drvdata(dev);
174
175 switch (type) {
176 case hwmon_pwm:
177 switch (attr) {
178 case hwmon_pwm_input:
179 if (val < MLXREG_FAN_MIN_DUTY ||
180 val > MLXREG_FAN_MAX_DUTY)
181 return -EINVAL;
182 return regmap_write(fan->regmap, fan->pwm.reg, val);
183 default:
184 return -EOPNOTSUPP;
185 }
186 break;
187
188 default:
189 return -EOPNOTSUPP;
190 }
191
192 return -EOPNOTSUPP;
193}
194
195static umode_t
196mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
197 int channel)
198{
199 switch (type) {
200 case hwmon_fan:
201 if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
202 return 0;
203
204 switch (attr) {
205 case hwmon_fan_input:
206 case hwmon_fan_fault:
207 return 0444;
208 default:
209 break;
210 }
211 break;
212
213 case hwmon_pwm:
214 if (!(((struct mlxreg_fan *)data)->pwm.connected))
215 return 0;
216
217 switch (attr) {
218 case hwmon_pwm_input:
219 return 0644;
220 default:
221 break;
222 }
223 break;
224
225 default:
226 break;
227 }
228
229 return 0;
230}
231
232static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
233 HWMON_CHANNEL_INFO(fan,
234 HWMON_F_INPUT | HWMON_F_FAULT,
235 HWMON_F_INPUT | HWMON_F_FAULT,
236 HWMON_F_INPUT | HWMON_F_FAULT,
237 HWMON_F_INPUT | HWMON_F_FAULT,
238 HWMON_F_INPUT | HWMON_F_FAULT,
239 HWMON_F_INPUT | HWMON_F_FAULT,
240 HWMON_F_INPUT | HWMON_F_FAULT,
241 HWMON_F_INPUT | HWMON_F_FAULT,
242 HWMON_F_INPUT | HWMON_F_FAULT,
243 HWMON_F_INPUT | HWMON_F_FAULT,
244 HWMON_F_INPUT | HWMON_F_FAULT,
245 HWMON_F_INPUT | HWMON_F_FAULT),
246 HWMON_CHANNEL_INFO(pwm,
247 HWMON_PWM_INPUT),
248 NULL
249};
250
251static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
252 .is_visible = mlxreg_fan_is_visible,
253 .read = mlxreg_fan_read,
254 .write = mlxreg_fan_write,
255};
256
257static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
258 .ops = &mlxreg_fan_hwmon_hwmon_ops,
259 .info = mlxreg_fan_hwmon_info,
260};
261
262static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
263 unsigned long *state)
264{
265 *state = MLXREG_FAN_MAX_STATE;
266 return 0;
267}
268
269static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
270 unsigned long *state)
271
272{
273 struct mlxreg_fan *fan = cdev->devdata;
274 u32 regval;
275 int err;
276
277 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
278 if (err) {
279 dev_err(fan->dev, "Failed to query PWM duty\n");
280 return err;
281 }
282
283 *state = MLXREG_FAN_PWM_DUTY2STATE(regval);
284
285 return 0;
286}
287
288static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
289 unsigned long state)
290
291{
292 struct mlxreg_fan *fan = cdev->devdata;
293 unsigned long cur_state;
294 u32 regval;
295 int i;
296 int err;
297
298 /*
299 * Verify if this request is for changing allowed FAN dynamical
300 * minimum. If it is - update cooling levels accordingly and update
301 * state, if current state is below the newly requested minimum state.
302 * For example, if current state is 5, and minimal state is to be
303 * changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
304 * from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
305 * overwritten.
306 */
307 if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
308 state -= MLXREG_FAN_MAX_STATE;
309 for (i = 0; i < state; i++)
310 fan->cooling_levels[i] = state;
311 for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
312 fan->cooling_levels[i] = i;
313
314 err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
315 if (err) {
316 dev_err(fan->dev, "Failed to query PWM duty\n");
317 return err;
318 }
319
320 cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
321 if (state < cur_state)
322 return 0;
323
324 state = cur_state;
325 }
326
327 if (state > MLXREG_FAN_MAX_STATE)
328 return -EINVAL;
329
330 /* Normalize the state to the valid speed range. */
331 state = fan->cooling_levels[state];
332 err = regmap_write(fan->regmap, fan->pwm.reg,
333 MLXREG_FAN_PWM_STATE2DUTY(state));
334 if (err) {
335 dev_err(fan->dev, "Failed to write PWM duty\n");
336 return err;
337 }
338 return 0;
339}
340
341static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
342 .get_max_state = mlxreg_fan_get_max_state,
343 .get_cur_state = mlxreg_fan_get_cur_state,
344 .set_cur_state = mlxreg_fan_set_cur_state,
345};
346
347static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
348 struct mlxreg_core_data *data)
349{
350 u32 regval;
351 int err;
352
353 err = regmap_read(fan->regmap, data->capability, ®val);
354 if (err) {
355 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
356 data->capability);
357 return err;
358 }
359
360 return !!(regval & data->bit);
361}
362
363static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
364 struct mlxreg_core_data *data)
365{
366 u32 regval;
367 int err;
368
369 err = regmap_read(fan->regmap, data->capability, ®val);
370 if (err) {
371 dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
372 data->capability);
373 return err;
374 }
375
376 /*
377 * Set divider value according to the capability register, in case it
378 * contains valid value. Otherwise use default value. The purpose of
379 * this validation is to protect against the old hardware, in which
380 * this register can return zero.
381 */
382 if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
383 fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
384
385 return 0;
386}
387
388static int mlxreg_fan_config(struct mlxreg_fan *fan,
389 struct mlxreg_core_platform_data *pdata)
390{
391 struct mlxreg_core_data *data = pdata->data;
392 bool configured = false;
393 int tacho_num = 0, i;
394 int err;
395
396 fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
397 fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
398 for (i = 0; i < pdata->counter; i++, data++) {
399 if (strnstr(data->label, "tacho", sizeof(data->label))) {
400 if (tacho_num == MLXREG_FAN_MAX_TACHO) {
401 dev_err(fan->dev, "too many tacho entries: %s\n",
402 data->label);
403 return -EINVAL;
404 }
405
406 if (data->capability) {
407 err = mlxreg_fan_connect_verify(fan, data);
408 if (err < 0)
409 return err;
410 else if (!err) {
411 tacho_num++;
412 continue;
413 }
414 }
415
416 fan->tacho[tacho_num].reg = data->reg;
417 fan->tacho[tacho_num].mask = data->mask;
418 fan->tacho[tacho_num++].connected = true;
419 } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
420 if (fan->pwm.connected) {
421 dev_err(fan->dev, "duplicate pwm entry: %s\n",
422 data->label);
423 return -EINVAL;
424 }
425 fan->pwm.reg = data->reg;
426 fan->pwm.connected = true;
427 } else if (strnstr(data->label, "conf", sizeof(data->label))) {
428 if (configured) {
429 dev_err(fan->dev, "duplicate conf entry: %s\n",
430 data->label);
431 return -EINVAL;
432 }
433 /* Validate that conf parameters are not zeros. */
434 if (!data->mask && !data->bit && !data->capability) {
435 dev_err(fan->dev, "invalid conf entry params: %s\n",
436 data->label);
437 return -EINVAL;
438 }
439 if (data->capability) {
440 err = mlxreg_fan_speed_divider_get(fan, data);
441 if (err)
442 return err;
443 } else {
444 if (data->mask)
445 fan->samples = data->mask;
446 if (data->bit)
447 fan->divider = data->bit;
448 }
449 configured = true;
450 } else {
451 dev_err(fan->dev, "invalid label: %s\n", data->label);
452 return -EINVAL;
453 }
454 }
455
456 /* Init cooling levels per PWM state. */
457 for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
458 fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
459 for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
460 fan->cooling_levels[i] = i;
461
462 return 0;
463}
464
465static int mlxreg_fan_probe(struct platform_device *pdev)
466{
467 struct mlxreg_core_platform_data *pdata;
468 struct device *dev = &pdev->dev;
469 struct mlxreg_fan *fan;
470 struct device *hwm;
471 int err;
472
473 pdata = dev_get_platdata(dev);
474 if (!pdata) {
475 dev_err(dev, "Failed to get platform data.\n");
476 return -EINVAL;
477 }
478
479 fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
480 if (!fan)
481 return -ENOMEM;
482
483 fan->dev = dev;
484 fan->regmap = pdata->regmap;
485
486 err = mlxreg_fan_config(fan, pdata);
487 if (err)
488 return err;
489
490 hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
491 fan,
492 &mlxreg_fan_hwmon_chip_info,
493 NULL);
494 if (IS_ERR(hwm)) {
495 dev_err(dev, "Failed to register hwmon device\n");
496 return PTR_ERR(hwm);
497 }
498
499 if (IS_REACHABLE(CONFIG_THERMAL)) {
500 fan->cdev = devm_thermal_of_cooling_device_register(dev,
501 NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
502 if (IS_ERR(fan->cdev)) {
503 dev_err(dev, "Failed to register cooling device\n");
504 return PTR_ERR(fan->cdev);
505 }
506 }
507
508 return 0;
509}
510
511static struct platform_driver mlxreg_fan_driver = {
512 .driver = {
513 .name = "mlxreg-fan",
514 },
515 .probe = mlxreg_fan_probe,
516};
517
518module_platform_driver(mlxreg_fan_driver);
519
520MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
521MODULE_DESCRIPTION("Mellanox FAN driver");
522MODULE_LICENSE("GPL");
523MODULE_ALIAS("platform:mlxreg-fan");